a slang or colloquial shortening of various nouns beginning in con-, such as, from the 19th century, confidant, conundrum, conformist, convict, contract, and from the 20th century, conductor, conservative.

word-forming element meaning "together, with," sometimes merely intensive; the form of com- used in Latin before consonants except -b-, -p-, -l-, -m-, or -r-. In native English formations (such as costar), co- tends to be used where Latin would use con-.

late 14c., "something formed in the mind, thought, notion," from conceiven (see conceive) based on analogy of deceit and receipt. Sense evolved from "something formed in the mind," to "fanciful or witty notion" (1510s), to "vanity" (c. 1600) through shortening of self-conceit (1580s).

late 13c., conceiven, "take (seed) into the womb, become pregnant," from stem of Old French conceveir (Modern French concevoir), from Latin concipere (past participle conceptus) "to take in and hold; become pregnant," from com-, intensive prefix (see com-), + comb. form of capere "to take," from PIE *kap- "to grasp" (see capable). Meaning "take into the mind" is from mid-14c., a figurative sense also found in the Old French and Latin words. Related: Conceived; conceiving.

1901, "compound for noncombatants in a war zone" (see concentration); a term for a controversial idea in the second Boer War (1899-1902), and the term emerged with a bad odor.

The concentration camp now definitely taken its place side by side with Black Hole of Calcutta as one of those of horror at which humanity will never cease shudder. ["The Review of Reviews," London, March 1902]

It also was used 1902 in reference to then-current U.S. policies in the Philippines, and retroactively in reference to Spanish policies in Cuba during the insurrection there of 1896-98. The phrase was used in U.S. during the Spanish-American war, but in reference to designated rendezvous points for U.S. troops headed overseas. In reference to prisons for dissidents and minorities in Nazi Germany from 1934, in Soviet Russia from 1935.

early 14c., "act of conceiving," from Old French concepcion (Modern French conception) "conception, grasp, comprehension," from Latin conceptionem (nominative conceptio) "a comprehending, conception," noun of action from stem of concipere (see conceive). Originally in the womb sense (also with reference to Conception Day in the Church calendar); mental sense "process of forming concepts" is late 14c. Meaning "that which is conceived in the mind" is from 1520s; "general notion" is from 1785.

In the Middle Ages, before the word entered English, the meaning shifted from "to strive against" to "to strive alongside." Sense of "public musical performance" is 1680s. But Klein considers this too much of a stretch and suggests Latin concentare "to sing together" (from con- + cantare "to sing") as the source of the Italian word in the musical sense.

mid-15c., from Old French concession (14c.) or directly from Latin concessionem (nominative concessio) "an allowing, conceding," noun of action from past participle stem of concedere (see concede). Meaning "right or privilege granted by government" is from 1650s. "Refreshment stand" sense is from 1910.

type of shell, early 15c., from Latin concha "shellfish, mollusk," from Greek konkhe "mussel, shell," from PIE root *konkho-. The name for natives of Florida Keys since at least 1833; the preferred pronunciation there ("kongk") preserves the classical one.

[Conciseness] is the English word familiar to the ordinary man: concision is the LITERARY CRITIC'S WORD, more recent in English, used by writers under French influence & often requiring the reader to stop & think whether he knows its meaning. [Fowler]

late 14c., "cutting away, mutilation," also, from 16c., "circumcision," from Latin concisionem "a separation into divisions," literally "a cutting up," noun of action from past participle stem of concidere "to cut up" (see concise). From 18c. it began to be used in the sense of conciseness (q.v.).

late 14c., "a place where cardinals meet to elect a pope," from Italian conclave, from Latin conclave "a room, chamber suite," probably originally "a room which may be locked," from com- "together" (see com-) + clavis "a key" (see slot (n.2)). Extended sense of "private assembly" is first recorded 1560s.

late 14c., "deduction or conclusion reached by reasoning," from Old French conclusion "conclusion, result, outcome," from Latin conclusionem (nominative conclusio), noun of action from past participle stem of concludere (see conclude). Also, from late 14c. "the end" (usually of speech or writing), "closing passages of a speech or writing."